1. Field of the Invention
The present invention relates generally to Power over Ethernet (PoE) and, more particularly, to a system and method for collecting power management parameters in a computing device for PoE.
2. Introduction
The IEEE 802.3af and 802.3at PoE specifications provide a framework for delivery of power from power sourcing equipment (PSE) to a powered device (PD) over Ethernet cabling. In this PoE process, a valid device detection is first performed. This detection process identifies whether or not it is connected to a valid device to ensure that power is not applied to non-PoE capable devices. After a valid PD is discovered, the PSE can optionally perform a power classification. The completion of this power classification process enables the PSE to manage the power that is delivered to the various PDs connected to the PSE.
Managing PDs such as VoIP phones, wireless LAN access points, Bluetooth access points, and network cameras is one of the tasks of the PSE. In general, a PSE is designed to provide stable output power to a PD. One example of such a PD is a portable computing device (e.g., laptop computer), which can have varying power requirements depending on the operation of its internal components. These internal components need not be uniform and can vary greatly between devices depending on the manufacturer and component suppliers. Moreover, power usage can be highly dependent on the application(s) running on the portable computing device. In one operating state, the portable computing device can be in a relatively idle state or performing simple tasks such as word processing. In another operating state, the portable computing device can be performing a variety of simultaneous tasks such as video encoding, disc burning, game playing, and even powering other USB devices. As would be appreciated, transitions between the various operating states can be rapid and continual as the usage requirements of the portable computing device change in accordance with the directives of the user. What is needed therefore is a mechanism for collecting various power management parameters for use in managing such PDs in a PoE system.